A Syrian refugee flashes a victory sign in the new refugee tent compound in Boynuyogun, Turkey, near the Syrian border. Photograph: Vadim Ghirda/AP

Almost six months on since we reported that the number of Syrian refugees had surpassed 1 million, what has changed?

How many

Since March, when the Syrian refugee community attracted international attention because of its sheer size, their number has continued to climb. More importantly, the rate of that increase has hastened.

In the last six months of 2012, a typical update from the UNHCR consisted of about 2,300 newly registered refugees. In the first six months of 2013, an average update had 7,300 refugees.

Today, the UN has registered more than 1.6 million refugees and acknowledges more than 200,000 who still await registration.

Interactive graph showing the number of Syrians registered as refugees by the United Nations. Click zoom or drag the borders of the lower graph to focus on a specific time period.

The rapid acceleration in displacement has far surpassed expectations - the UN had initially estimated that the number of refugees would only reach 1 million by the middle of 2013.

The UN agency has detailed plans about how best to address the needs of those refugees in 2013. But it claims that it needs almost $3bn to carry that out and has so far only received 38% of the funds it needs - it is not yet clear how the $1.8bn funding gap will be filled.

Where to

With limited options, the refugees' destinations have been concentrated in the region. Lebanon currently hosts more than half a million Syrian refugees, Jordan 440,000 and Turkey 410,000 with Iraq and Egypt having smaller numbers - 161,879 and 75,456 respectively.

However, those totals are highly misleading. They suggest a community of Syrians, which though fragmented are distributed relatively evenly throughout the region. Focusing on the proportion of the total refugee population in each country fails to observe how Syrians face entirely different challenges in each of these states - and how these countries face entirely different challenges when Syrians cross their borders.

Lebanon, a country of around 4.4 million and about the same in territorial size as Cyprus, has found it hard to absorb the huge number of Syrians seeking refuge there. In Jordan, the country's efforts to deal with 450,000 Iraqi refugees have to be managed alongside the new influx of Syrians.

Refugee population

The demographics of Syria's refugees have changed slightly since we last reported on this in March 2013. Then, 52% of refugees were women. Now, that proportion has declined to 47.5%.

More worrying, however, is the age profile of vulnerable Syrians forced from the country - more than half are under 17 years of age and 38% are younger than 11. Some of these children have been separated from their parents. Others are born as refugees.

Who's helping

The United Nations is continually revising its Regional Response Plan - the latest of these updates was just three days ago.

It shows where the money is going and which organisations are most in need of additional funds. Of the $1.1bn of funding that has been received in the region so far in 2013, the largest sums have gone to Jordan and Lebanon.

Just five organisations have received 100% of the funds they need to assist the Syrian refugees. The World Food Programme has so far only found 17% of the money it requires, while International Medical Corps has just 7%.

The US is the largest single donor, contributing $228.5m - 43% of all donor funding. Kuwait, which has so far given $112m, is the second most generous in terms of total values given.

Private donors account for $8.7m, which is more than the money given by Switzerland, Ireland, Sweden, Austria and Belgium combined.

Additional challenges

Reading the UN's response plans, one term sheds a great deal of insight into the lives of Syria's refugees - "unmet needs".

Here are just some of the examples of the difficulties they face:

Lebanon: • Syrians are detained for illegal entry or stay in the absence of clear operational guidance for law enforcement personnel. The UNHCR is not always informed• Not all refugees approach the UNHCR for registration, despite outreach.• Child trafficking and child labour • Limited coverage and capacity of specialised psycho-social and mental health services

Jordan: • No systematic and regular border monitoring by UNHCR. • No governmental system in place to separate civilians from non-civilians seeking asylum in Jordan• 200,000 children (64%) are not assisted to pursue their education • 60% of refugees with mental health disorders are not covered

Turkey: • 40% of the camps have no refugee committees• Vulnerable third-country nationals are not provided with evacuation assistance and are unable to return to their countries of origin• No projects targeting vulnerable host communities• No central warehouse for aid provisions

Iraq: • Uncertainty as to when al-Qa'im border between Syria and Iraq will reopen•Refugees living outside camps cannot be reached with food assistance

Egypt:• Limited child protection services • Information sessions are needed on residency and legal and security rules, marriage and power of attorney • Difficulties for refugees to obtain work authorisation are compounded by lack of available jobs